mysql - codeigniter 在 find_in_set 中添加 IS NULL

Question

同时通过 codeigniter 框架生成查询

$this->db->select('id,memo,sent_to,sent_by,read_by,date')->from('memos')
    ->where("FIND_IN_SET('1',`sent_to`)")->order_by('`id`','DESC')->get();

我在查询中自动添加 IS NULL 时出错

它产生

SELECT `id`, `memo`, `sent_to`, `sent_by`, `read_by`, `date` FROM `memos` 
WHERE FIND_IN_SET('1',`sent_to`) IS NULL ORDER BY `id` DESC 

代替

SELECT `id`, `memo`, `sent_to`, `sent_by`, `read_by`, `date` FROM `memos` 
WHERE FIND_IN_SET('1',`sent_to`) ORDER BY `id` DESC

Answer 1

下面的代码 100% 有效。试试吧，

    $this->db->select('id,memo,sent_to,sent_by,read_by,date');
    $this->db->from('memos');
    $this->db->where("FIND_IN_SET('1',`sent_to`) !=", 0);
    $this->db->order_by('`id`','DESC');
    $this->db->get();